Maurice Dyer Posted July 18, 2022 Share Posted July 18, 2022 Hi Inherited this O.S 70 four stroke from an ex member. Runs well, good compression, I just cannot find any info on this type of O S from any website. Notice the fuel tube connecting the crankcase and the inlet manifold. There is no other oil egress anywhere. As I said, it runs well enough, just makes a noise like my old mum's Rolls Rapide twin tub used to. Anybody anyone ?? Quote Link to comment Share on other sites More sharing options...
Jon H Posted July 18, 2022 Share Posted July 18, 2022 70 surpass II. It was covered under the same manual as the 91 surpass II https://www.os-engines.co.jp/english/line_up/engine/air/single/manual/fs70-91s2_series.pdf Still got my 91 SII. Nice engine and currently in hibernation. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted July 18, 2022 Share Posted July 18, 2022 Not the same,,, http://dieselrc.com/download/os_fs-70s.pdf I had one, in my opinion the best 4 stroke that OS made, followed by the .48 Surpass,,, Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted July 18, 2022 Author Share Posted July 18, 2022 Much obliged Jon. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 18, 2022 Share Posted July 18, 2022 Os got the 70 and 90 spot on , well sorted engines. Just check the crank and cam bearings as these can cause a drop in performance if worn as they will affect valve timing. Check with a prop rock when engine is at TDC. Quote Link to comment Share on other sites More sharing options...
David Davis Posted July 18, 2022 Share Posted July 18, 2022 They also made a cheaper version the FL 70. I have one in a 1/6 scale BE2e. It seems fine to me but I don't fly the BE2 every day. 1 Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted July 18, 2022 Author Share Posted July 18, 2022 10 minutes ago, David Davis said: They also made a cheaper version the FL 70. I have one in a 1/6 scale BE2e. It seems fine to me but I don't fly the BE2 every day. That's a lovely model Sir. Kit, plan or ?? Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted July 18, 2022 Share Posted July 18, 2022 I have three OS70 F/S engines. They are all elderly but are superb and run like Swiss watches (on Prosynth fuel, obviously). @Maurice: If yours grumbles whilst running, it probably needs new crankshaft bearings. Depending on the life it has had, it is worth checking the camshaft bearings too. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 18, 2022 Share Posted July 18, 2022 Agree with all the above. Run really nicely. Quote Link to comment Share on other sites More sharing options...
David Davis Posted July 19, 2022 Share Posted July 19, 2022 14 hours ago, Maurice Dyer said: That's a lovely model Sir. Kit, plan or ?? I'm ashamed to say that I bought it from a bereavement sale! I was in the process of building my own from a short-kit but needless to say my model remains only partly built. I also acquired a complete kit of the same model. I suppose I ought to sell it, I don't need three BE2s! The model was designed by Roy Scott. The plan is available on The Outerzone: https://outerzone.co.uk/plan_details.asp?ID=6303 I could have sworn that my short-kit came from either Belair or Flying Scale Models, now Sarik, but I can't find any reference to to it on either site. Quote Link to comment Share on other sites More sharing options...
David Davis Posted July 19, 2022 Share Posted July 19, 2022 P.S. I have just pulled the box from underneath some other kit boxes and I was right. It was supplied by Belair Kits, their code: BE2ADH, but it does not seem to be listed now. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted July 19, 2022 Share Posted July 19, 2022 ADH gave it away🙂 Doolittle Media Shop | BE2 & BE 2a cut parts for plan503 (adhpublishing.com) Steve Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted July 19, 2022 Share Posted July 19, 2022 and the plan Doolittle Media Shop | BE2 & BE 2a 84.1″ Plan503 (adhpublishing.com) Steve Quote Link to comment Share on other sites More sharing options...
David Davis Posted July 19, 2022 Share Posted July 19, 2022 (edited) This is not the same model EB. This model is listed as a Be2 or BE2a by Gary Sunderland not the BE2e of Roy Scott. Now I don't want to come across as a complete anorak but the BE2 and BE2a had wing warping for roll control. So did the BE2b for that matter. The model illustrated in your links is a BE2c, the ailerons, the four interplane struts and the small triangular fin give it away. The BE2e had only two interplane struts, a different wing planform and different tail surfaces. Edited July 19, 2022 by David Davis Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted July 19, 2022 Share Posted July 19, 2022 I did notice but was not that interested in the detail. I was just trying to follow the clues and hopefully help but now feel like I am being told off. Steve Quote Link to comment Share on other sites More sharing options...
David Davis Posted July 19, 2022 Share Posted July 19, 2022 Sorry EB. I didn't mean to sound critical it's just that Gary Sunderland's model is different to Roy Scott's. Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted July 19, 2022 Author Share Posted July 19, 2022 19 hours ago, Brian Cooper said: I have three OS70 F/S engines. They are all elderly but are superb and run like Swiss watches (on Prosynth fuel, obviously). @Maurice: If yours grumbles whilst running, it probably needs new crankshaft bearings. Depending on the life it has had, it is worth checking the camshaft bearings too. Thanks Brian. It's not rumbling, it's more like a sink plunger being used.(aggressively) !!! Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted July 20, 2022 Share Posted July 20, 2022 On 19/07/2022 at 11:56, Maurice Dyer said: Thanks Brian. It's not rumbling, it's more like a sink plunger being used.(aggressively) !!! WOW. . . I can't say this is a sound with which I am familiar in an engine. I would love to hear it running. Quote Link to comment Share on other sites More sharing options...
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